SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96cd34db6904df66cdf3d6f60f66c2e247b1faef823472e6b284f4d85a66c6be' 
  AND token = 'LnbLiLqnrP/v1+UNBQDlAGODCKKbxOeIBOkYcjY1ZTg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}